Brown Oxide Research Articles

Dietary Silk Peptide Prevents High-Fat Diet-Induced Obesity and Promotes Adipose Browning by Activating AMP-Activated Protein Kinase in Mice.

Obesity is associated with metabolic syndrome and other chronic diseases, and is caused when the energy intake is greater than the energy expenditure. We aimed to determine the mechanism whereby acid-hydrolyzed silk peptide (SP) prevents high-fat diet-induced obesity, and whether it induces browning and fatty acid oxidation (FAO) in white adipose tissue (WAT), using in vivo and ex vivo approaches. We determined the effects of dietary SP in high-fat diet-fed obese mice. The expression of adipose tissue-specific genes was quantified by western blotting, qRT-PCR, and immunofluorescence analysis. We also investigated whether SP directly induces browning in primarily subcutaneous WAT-derived adipocytes. Our findings demonstrate that SP has a browning effect in WAT by upregulating AMP-activated Protein Kinase (AMPK) phosphorylation and uncoupling protein 1 (UCP1) expression. SP also suppresses adipogenesis and promotes FAO, implying that it may have potential as an anti-obesity drug.

3001 Published By: Blue Eyes Intelligence Engineering & Sciences Publication Retrieval Number: B8113129219/2019©BEIESP DOI: 10.35940/ijitee.B8113.129219 Journal Website: www.ijitee.org Age Hardening in COR-Ten Steel

Weathering steels developed under the name COR-TEN steels, established themselves as a promising material to meet the demand for atmospheric corrosion resistance and eliminate the need for painting. COR-TEN steel is resistant to corrosive effect of weather such as rain, snow, ice, fog, etc. A coating of dark brown oxidation is developed over the metal surface, when it comes in contact with the environment thereby inhibiting the deeper penetration and negating the need for painting and reducing the rust-prevention cost over the years. Thus the steel is allowed to rust which forms a protective layer and slows down the rate of corrosion. The present study emphasizes the age hardening behavior of COR-TEN steel. The steel was subjected to solution treatment at 1000°C following accelerated cooling with water, oil and air. The oil quenched steel was then subjected to aging treatment at 400°C and 500°C for various times ranging from 5 min to 1500 min followed by water quenching. In order to ascertain the response to aging hardness measurement were conducted by employing a load of 20 Kgf. Metallographic examinations were also conducted to study the resulting structural transformations in various stages of investigations.

Optimized biological tools: ultrastructure of rodent and bat teeth compared to human teeth

Enamel, the outer layer of the teeth of vertebrates, is the hardest tissue in their body. In general, enamel is highly mineralized and has a special ultrastructure that directs the mechanical properties of teeth and thereby their biological functions. However, there are differences between the enamel ultrastructures of different species. The authors compare the teeth of the Eurasian beaver Castor fiber, the African mole rat Fukomys kafuensis and the common pipistrelle bat Pipistrellus pipistrellus by high-resolution analytical methods, including scanning electron microscopy, quantitative wavelength-dispersive X-ray spectroscopy and X-ray powder diffraction. The enamel of all animals consists of long, thin and differently oriented calcium phosphate crystallites (length > 1 µm; thickness about 50 nm). On the outer surface of the beaver tooth, a thin layer of brown iron oxide was found. The diameter of the dentin tubuli was between 1 and 3 µm for all species – that is, comparable to that for human teeth.

Walnut (Juglans regia L.) kernel postharvest deterioration as affected by pellicle integrity, cultivar and oxygen concentration

Increased demand for convenient, healthy foods has promoted the commercialization of shelled, more perishable walnut kernels. In this work for two of the major commercial walnut cultivars (‘Chandler’ and ‘Howard’) we determined the influence that disruption of the integrity of the seed coat pellicle during shelling operations trigger postharvest deterioration. Commercially mature ‘Chandler’ and ‘Howard’ nuts were subjected to Gentle (GS, <4% pellicle area damaged per kernel) or Harsh Shelling (HS, 20–22% of pellicle area damaged) and stored in air at 25 or 35 °C (accelerated aging) for three or six weeks. During this period, which simulated current marketing and retail display, we evaluated kernel color changes (Dried Fruit Association of California ‘DFA’ scale, L* and Hue), ethanol-soluble phenolic antioxidants, oil-free fatty acids (FFA), and peroxide value (PV). The kernel color changed from ‘light’ to ‘amber’ during storage, as demonstrated by the decrease in extra light and light kernels and by the reduced lightness (L*) and Hue values. Pellicle browning (amber) incidence was common on HS kernels, which also lost more phenolic antioxidants during storage. Minimizing pellicle damage by GS operations reduced triglyceride hydrolysis and peroxidation. Kernel quality loss was largely dependent on cultivar; browning oxidation, and lipid hydrolysis and oxidation were faster in ‘Howard’ than in ‘Chandler’. Searching for a practical and direct postharvest technology, in absence of proper temperature control, to reduce the rate of kernel deterioration, we tested controlled atmospheres (CA) at different O2 concentrations (0.0, 3.0, 6.0 or 21.0 kPa) on both cultivars. Overall, commercially shelled ‘Howard’ and ‘Chandler’ (kernels) will benefit from retail packaging with oxygen concentrations equal to or lower than 3.0 kPa during warm retail display. This information will be useful for processors, distributors and produce handlers to protect snack-friendly, ready-to-eat walnuts.

Bulging rupture and caustic corrosion of a boiler tube in a thermal power plant

This paper presents a failure analysis of a boiler tube (SA-210 Grade A-1) in a low sulfur waxy residue (LSWR) oil-fired plant. A highly deformed bulged rupture was observed on the outside of the tube, and the steam from the rupture damaged the tube adjacent to the failed tube. Severe thickness reduction was observed on the inner surface, and brown and orange oxides and white scale were present in the failure region. Microstructural examination and hardness tests confirmed that material degradation (voids, microcracks, and decreased hardness) caused by overheating at the failure region had taken place. X-ray diffraction analysis indicated the presence of CaSiO2 and Na2FeO2, indicating caustic corrosion. In addition, dimples and striations were observed in scanning electron microscopy fractography results. We therefore concluded that deposits on the interior wall led to overheating, followed by evaporation of the feed water, and then NaOH in the water caused caustic corrosion. Eventually, this corrosion resulted in ductile and fatigue failure arising from internal pressure and thermal fatigue.

Paleo-Hydrothermal Predecessor to Perennial Spring Activity in Thick Permafrost in the Canadian High Arctic, and Its Relation to Deep Salt Structures: Expedition Fiord, Axel Heiberg Island, Nunavut

Paleo-Hydrothermal Predecessor to Perennial Spring Activity in Thick Permafrost in the Canadian High Arctic, and Its Relation to Deep Salt Structures: Expedition Fiord, Axel Heiberg Island, Nunavut

Effect of an Initiating Additive of CuSO4 on Changes in the Characteristics of Brown Coal Oxidation and Pyrolysis

The oxidation and pyrolysis of brown coal containing 5 wt % CuSO4 as an initiating additive was studied. The experiment was performed by thermogravimetry at a heating rate of 2.5 K/min in an atmosphere of air and nitrogen. The process characteristics in the pyrolysis and oxidation mode were evaluated, and the activation energy of the process was determined by the Coats–Redfern method. It was established that the addition of the initiating agent CuSO4 led to a significant decrease in the initial temperature of oxidation and pyrolysis processes to shift the reaction toward the low-temperature region. Maximum changes in the reaction initiation temperatures in the oxidation (ΔTi) and (ΔTd) pyrolysis modes were 35 and 50°С, respectively. It was established that the introduction of CuSO4 led to a decrease in the activation energy of oxidation by 7.1 kJ/mol, and ΔEa was 10 kJ/mol for the pyrolysis process. A decrease in the residence times of a sample within the limits of the sublimation of volatile substances was observed: Δti was 12 min for oxidation, and Δtd was 18 min for pyrolysis. According to mass-spectrometric analysis data, the presence of SO2 (peaks at 230 and 320°C) was detected in the oxidation and pyrolysis reaction products of modified samples; this was explained by the chemical interaction of copper sulfate with brown coal components.

Copper induced direct CO2 laser drilling blind hole with the aid of brown oxidation for PCB CCL

CO2 laser drilling of blind hole is the necessary process to obtain high-density connection between different conductive layers for printed circuit board (PCB). A copper induced direct CO2 laser drilling blind hole was proposed to simplify the working process and enhance hole alignment with the aid of copper brown oxidation. Brown oxidized copper holding a roughened surface to extend the laser route in its surface and copper oxidation of CuO with a high laser absorptivity were investigated by scanning electron microscopy (SEM), 3D microscope, X-ray photoelectron spectroscopy (XPS), infrared thermal camera, and metallographic microscopy. It therefore breaks the limitation of pure copper stripped by CO2 laser. Example for CCL of top copper with thickness of 18 μm and dielectric resin with thickness of 80 μm realized the qualified Φ100 μm blind hole under 45 mL/L brown oxidation solution for 90 s.

Effects of phosphorus on absorption and transport of selenium in rice seedlings.

The effects of different concentrations of phosphorus (P) on absorption and transfer of selenium (Se) in rice seedlings were studied by hydroponics experiment. The interaction between iron plaque and phosphorus on absorption and transport of selenium were studied by adding a large amount of iron-induced iron plaque, to provide a theoretical basis for rational application of phosphate fertilizer in the selenium bio-strengthening process of rice. The results showed that phosphorus deficiency may result in the formation of reddish brown iron oxide coating on the root surface of rice. The formation of root iron plaque of rice is related to concentration of phosphorus, and low concentration of phosphorus (0-1.5mmolL-1) can increase the amount of root iron plaque. Compared P deficiency culture and 2mmolL-1 P culture, Se content in the shoots and roots decreased by 76 and 47%, respectively. Addition of Fe2+ significantly reduced biomass of shoot and had no significant effect on the roots; when the P concentration increased from 0.1 to 0.3mmolL-1, transfer coefficient of Se decreased. Therefore, both root iron plaques induced by phosphorus deficiency and iron addition have a strong adsorption effect on selenium, which reduces the transport of selenium from the rice roots to the shoots. In the lower range of phosphorus concentration, low phosphorus can promote selenium content of rice shoot, while higher on the contrary. In the practice of rice production, proper management of phosphorus nutrient is of great significance to control selenium content in rice grain.

Preparation of Brown Iron Oxide from Secondary Raw Material

The preparation of inorganic brown pigment from red mud is investigated. The results of the phase and chemical analyses of raw material and the product are given. A flow diagram is proposed and the parameters of the pigment production are recommended. This approach has provided a pigment of pure color with the opacity of 8 to 10 g m–2 from red mud (up to 80%) without additives and the reduction of Fe(III) into Fe(II) using sulfide sulfur.

Anti-Oxidative and Antibacterial Self-Healing Edible Polyelectrolyte Multilayer Film in Fresh-Cut Fruits.

The consumption of fresh-cut fruits is limited because of the oxidation browning and pathogenic bacteria's growth on the fruit surface. Besides, crack of the fresh-keeping film may shorten the preservation time of fruit. In this work, polyelectrolyte multilayer (PEM) film was fabricated by layer-by-layer (LBL) electrostatic deposition method. The film was made by carboxy methylcellulose sodium (CMC) and chitosan (CS). The as-prepared PEM film had good anti-oxidative and antibacterial capability. It inhibited the growth of Gram-negative bacteria and the antibacterial rate was more than 95%. The stratified structure and linear increase of the absorbance in the film verified a linear increase of film thickness. The slight scratched film could self-heal rapidly after the stimulation of water whatever the layer number was. Moreover, the film could heal cracks whose width was far bigger than the thickness. The application of PEM film on fresh-cut apples showed that PEM film had good browning, weight loss and metabolic activity inhibition ability. These results showed that the PEM film is a good candidate as edible film in fresh-cut fruits applications.

Mineralogy and genesis of the Ni–Co lateritic regolith deposit of the Çaldağ area (Manisa, western Anatolia), Turkey

The Çaldağ Ni–Co deposit is characterized by a reddish brown oxide lateritic regolith, containing residual Ni deposit formed by the intense tropical weathering of peridotites. Nickel–Co ore is associated with transported ferricrete during the late Paleocene – middle Eocene, represented by colloform Fe oxides and residual lateritization during the Oligocene. The lateritic regoliths are developed over dunitic ultramafic rocks and consist mainly of smectite, berthierine, kaolinite, gypsum, pyrite, takovite, and pecoraite. These units were examined using polarized-light microscopy, X-ray diffraction, scanning and transmission electron microscopy, and geochemical methods. Mineralogical zonation from the base of the profile upwards has the following zones: ultramafic bedrocks, serpentinized ultramafic rocks (saprock), saprolite, carbonate- and sulfide-bearing zone, ferruginous saprolite zone, and silcrete. In addition, Fe oxides, smectite and opal-CT, and quartz increase towards the surface, whereas olivine, pyroxene, and serpentine decrease upwards in response to chemical weathering. Nickel–Co mineralization associated with Fe oxides and smectitic clays formed under wet and dry conditions, respectively, as a result of an increased Fe2O3+ Al2O3+ Ni + Co/MgO ratio. Field observations and mineralogical and geochemical analyses reveal that the smectite formed under basic conditions was controlled by multistage chemical weathering of ultramafic and volcanic rocks and by the concentrations of Si, Al, Fe, and Mg. Locally, concentrations of S in conjunction with Fe and Ca resulted in precipitation of goethite–hematite, gypsum, and pyrite in dissolution voids in association with smectite under acidic conditions that developed in a well-drained system.

Improving interfacial adhesion between copper foil and resin using amino acid in printed circuit board industry

The corrosion inhibitor of nitrogen-containing amino acid histidine (His) has been applied in brown oxidation solutions and the relationships between brown oxidation solutions with the various concentrations of His and the adhesion strength of copper/resin laminates have been systematically studied by various testing techniques, including electrochemical impedance spectroscopy (EIS), peeling strength and field emission scanning electronic microscope. The result obtained from EIS suggested that His exhibited excellent anti-corrosive performance which contributed to a higher stability of the organic metallic film post brown oxidation process treatment. The roughness surface like honeycomb structure was gained and peel strength of the Cu/resin laminates was raised up to 0.71 kg/cm by altering the concentration of His in brown oxidation solutions. Moreover, theoretical calculations manifested that the studied inhibitor was almost adsorbed in parallel on the copper surface and X-ray photoelectron spectroscopy (XPS) declared that the value of adhesion strength was related to the surface chemistry of copper foil and resins after the lamination process which may attribute to chemical reactions at the copper/resin interface.

The effect of densification with NaOH on brown coal thermal oxidation behaviour and structure

The thermal behaviour and chemical structure of densified products of two Victorian brown coals prepared with NaOH addition were analysed by differential gravimetric analysis/differential thermal analysis (DGA/DTA) and Fourier transform infrared spectroscopy (FTIR).Acid washing of coal led to lower tendency to spontaneous combustion through a decrease in the total enthalpy change and a shift of the main mass loss stages to higher temperatures due to strengthening coal hydrogen bonding network.The addition of a small amount of NaOH (such that pH < 7.5) shifted the main stages of the DTG/DTA curves to lower temperatures and had a catalytic effect on spontaneous combustion by disrupting the hydrogen bonds network and suppressing cross-linking reactions. The products densified with higher amount of NaOH (such that pH ≥ 7.5) showed lower proportions of mass loss at lower temperatures stages of the DGA/DTA curves during oxidation with air. The ion exchange of Na ions for hydrogen in acid functional groups, increases the polarity and strength of bonds leading to a more rigid coal structure, reduces the surface area and decreases the coal’s tendency to react with oxygen and consequently delays the onset of combustion.FTIR results showed that the order of thermal vulnerability of brown coal’s functional groups toward decomposition/oxidation was as follows: aliphatic groups > carboxylic groups > carboxylate and aromatic groups > substituted aromatic groups ≈ polymerized ethers and ketones.

Change of brown coal oxidation kinetic characteristics by promoting additives appending in the form of copper salts

Process of brown coal oxidation with 5%wt content of copper-salt additives of various nature (Cu (NO3)2, CuSO4 and Cu(CH3COO)2) was studied. The experiment has been performed by thermogravimetric analysis at a heating rate of 2.5°C/min to a maximum temperature of 600°C in the air. Analytical evaluation of oxidation process kinetic characteristics has been conducted based on the results of TGA. It has been established that addition of initiating agents leads to significant reduction in the initial ignition temperature of coal (ΔTi = 15÷40°C), shortening of the sample warm-up time to the ignition point (Δte = 6÷12 min) and reduction of the sample burning time (Δtf = 40÷54 min). The following series of additives activity affecting ignition temperature of coals has been established: Cu(CH3COO)2 > Cu(NO3)2 > CuSO4. Additionally, the opposite can be said about the effect of additives on residence time of the sample in its combustion area (CuSO4 > Cu(NO3)2 > Cu(CH3COO)2). According to mass spectrometric analysis, presence of NOx, SO2, CO2 (intense peaks at 190÷290°C) was recorded in oxidation products of modified samples, which is explained by partial or complete decomposition of salts.

Wear Resistance Performance of Conventional and Non-Conventional Wind Turbine Blades with TiN Nano-Coating

Efficiency and durability are critical issues that affect widely-adopted aerofoil-power generator as a sustainable source of electrical power. Even though high wind power density can be achieved; installing wind turbines in desert condition has difficulties including thermal variation, high turbulence and sand storms. Sand blasting on turbine blade surface at high velocities causes erosion resulting turbine efficiency drop. Damage-induced erosion phenomena and aeroelastic performance of the blades needed to be investigated. Suitable coating may prevent erosion to a great extent. A numerical investigation of erosion on NACA 4412 wind turbine blade has been performed using commercial computational fluid dynamics software ANSYS FLUENT 14.5 release. Discrete phase model (DPM) has been used for modelling multi-phase flow of air and sand particles over the turbine blade. Governing equations have been solved by finite volume method (FVM). Conventional 30-70% glass fibre resin and non-conventional jute fibre composite have been used as turbine blade material. Sand particles of diameter have been injected from 20, 30, 45, 60 and 90 degree angles at 500C temperature. Erosion rate, wall shear stress and strain rate have been calculated for different wind velocities and impingement angles. Simulation results for higher velocities deviate from the results observed at lower wind velocities. In simulation, erosion rate is highest for impingement angle at low wind velocities, which has been validated by experiment with a mean absolute error (MAE) of 5.56%. Erosion rate and wall shear stress are higher on jute composite fibre than glass fibre resin. Developed shear stress on wind turbine blade surface is highest for impingement angle at all velocities. On the other hand, exerted pressure on turbine blade surface is found highest for 9 angle of attack. Experimental results, with or without Titanium nitride(TiN) nano-coating, also revealed that surface roughness augments with increasing impingement angles. Nano-coating (TiN) by RF sputtering technique reduced the surface roughness significantly as oppose to uncoated samples. Highest roughness has been observed on uncoated blade surface collided with 0.3-0.69 mm diameter brown aluminium oxide particles.

Fabrication and surface treatment of fine copper lines for HDI printed circuit board with modified full-additive method

PurposeThis paper aims to propose a modified full-additive method (MFAM) to fabricate fine copper lines for high density interconnection (HDI) printed circuit boards (PCBs). In addition, the surface of the fine copper lines is treated with a brown oxidation process to obtain good adhesion between the copper and the dielectric resin.Design/methodology/approachFine copper lines fabricated by MFAM were observed to evaluate the undercut quality, in comparison to undercut quality of copper lines fabricated by the semi-additive method and the subtractive method. The effect of the thickness of the dry film on the quality of the copper plating was investigated to obtain the regular shape of fine lines. The fine copper lines treated with the brown oxidation process were also examined to generate a coarse surface microstructure to improve the adhesion between the copper and the dielectric resin. The cross section and surface of as-fabricated fine copper lines were characterized using an optical microscope, a scanning electron microscope and an atomic force microscope.FindingsMFAM has the potential to fabricate high-performance fine copper lines for HDI PCBs. Undercut of as-fabricated fine copper lines could be prevented to meet the design requirement of impedance. In addition, fine copper lines exhibit enough adhesive force to laminate with dielectric resin after the brown oxidation process.Originality/valueMFAM, with the advantages of high efficiency and being a facile process, is developed to fabricate high-quality fine copper lines for industrial HDI PCB manufacture.

Incorporation of Tin on copper clad laminate to increase the interface adhesion for signal loss reduction of high-frequency PCB lamination

A novel method of improving the adhesion between copper and prepreg in high frequency PCB was proposed and studied in this work. This process which aimed to decrease the IEP (isoelectric point) of the copper to obtain higher adhesion, was achieved by depositing a thin tin layer with lower IEP on copper. It was characterized by scanning electron microscopy (SEM), 3D microscope, peel strength test, X-Ray thickness test, grazing incidence X-ray diffraction (GXRD), X-ray photoelectron spectroscopy (XPS), Agilent vector network analyzer (VNA), which confirmed its excellent adhesion performance and outstanding electrical properties in high-frequency signal transmission compared with traditional brown oxide method. Moreover, the mechanism of achieving high adhesion for this method was also investigated.

Chemoselective oxidation of aryl organoboron systems enabled by boronic acid-selective phase transfer.

We report the direct chemoselective Brown-type oxidation of aryl organoboron systems containing two oxidizable boron groups. Basic biphasic reaction conditions enable selective formation and phase transfer of a boronic acid trihydroxyboronate in the presence of boronic acid pinacol (BPin) esters, while avoiding speciation equilibria. Spectroscopic investigations validate a base-promoted phase-selective discrimination of organoboron species. This phenomenon is general across a broad range of organoboron compounds and can also be used to invert conventional protecting group strategies, enabling chemoselective oxidation of BMIDA species over normally more reactive BPin substrates. We also demonstrate the selective oxidation of diboronic acid systems with chemoselectivity predictable a priori. The utility of this method is exemplified through the development of a chemoselective oxidative nucleophile coupling.

Influence of shielding gas on the mechanical and metallurgical properties of DP-GMA-welded 5083-H321 aluminum alloy

In the present research, 6-mm-thick 5083-H321 aluminum alloy was joined by the double-pulsed gas metal arc welding (DP-GMAW) process. The objective was to investigate the influence of the shielding gas composition on the microstructure and properties of GMA welds. A macrostructural study indicated that the addition of nitrogen and oxygen to the argon shielding gas resulted in better weld penetration. Furthermore, the tensile strength and bending strength of the welds were improved when oxygen and nitrogen (at concentrations as high as approximately 0.1vol%) were added to the shielding gas; however, these properties were adversely affected when the oxygen and nitrogen contents were increased further. This behavior was attributed to the formation of excessive brown and black oxide films on the bead surface, the formation of intermetallic compounds in the weld metal, and the formation of thicker oxide layers on the bead surface with increasing nitrogen and oxygen contents in the argon-based shielding gas. Analysis by energy-dispersive X-ray spectroscopy revealed that most of these compounds are nitrides or oxides.